According to the investigative reporting center, Shasta Regional in Redding, Calif., was aggressively billing--upwards of 70 times the state average--for the rare malnutrition disorder found in developing countries.

Although Prime told the news outlet its billings are legal and accurate, the abrupt change in kwashiorkor rates could suggest they were incorrect in the first place, Jamie Bennett, a lawyer at the Maryland firm Ashcraft & Gerel, told California Watch.

"Someone told (the hospital) the billings were incorrect and they stopped; it's the only explanation," Bennett said.

After media reports about the alleged upcoding and an advisory notice from the American Hospital Association stating kwashiorkor is "extremely rare in the United States," records indicate that nine Prime hospitals that previously had billed Medicare for treating kwashiorkor reported no cases in 2011.

Last month, Prime Healthcare was fined $95,000 after state officials determined that executives leaked patient records to the media, violating patient confidentiality. In an attempt to defend its billing practices, Shasta Regional Medical Center CEO Randall Hempling and Chief Medical Officer Marcia McCampbell revealed the full chart of a patient to her hometown newspaper, Redding Record Searchlight, as well as medical exam results to the Los Angeles Times.

Prime Healthcare Services is a top 15 health system recognized by Thomson Reuters.

Earlier this month, California Watch issued a memo to readers, standing by its reporting.

It's unclear whether the alleged high rates of kwashiorkor are a result of diagnostic coding changes or intentional fraud, California Watch noted.

Similarly, Kernan Hospital in Baltimore faces allegations that diagnosis of kwashiorkor at Kernan jumped from zero cases in 2004 to 287 in 2007, according to the Department of Health & Human Services and Department of Defense, which filed suit in October 2011.